Using isolated, in vitro, systems, it is intended to study the relationship between neurotransmitter effects on receptors and the synthesis and secretion of neurosecretions. The long-term goal is to characterize systems which are physiologically regulated by cholinergic and adrenergic mechanisms in the brain. Cultured supra-optic nucleus cells of puppies will be studied as an example of a cholinergically driven system, and the pineal will be studied as an example of an adrenergically driven system. Attempts will be made to develop other neurosecretory cell culture systems for future study.